The present invention pertains to an apparatus used in handling communications through a telephone circuit designed to accommodate a large volume of communications. In particular, the invention under review pertains to an apparatus for the transmission and reception of data in which the transmission and reception of control signals between a movable telephone and an apparatus for transmission and reception of data is handled by serial data transmissions when communications, such as facsimile communications or telephone calls, are processed therethrough.
There has been much demand for car telephones and portable telephones that can handle communications in volume. With these kinds of telephones, which have been designed to handle a large volume of communications, transmission and reception of control signals between the movable telephone and the circuit connector are handled by serial data transmissions.
Nevertheless, should there be errors in transmission and reception of control signals originating in serial data signals between the movable telephone equipment and the apparatus for transmission and reception of data, there will be errors in acknowledgment made between the movable telephone and the apparatus for transmission and reception of data. For example, in Japanese Kokai No. 62-180655 (1987), there is discussion of an apparatus for transmission and reception of data that detects "on hook" signals and "off hook" signals in a telephone, and then, pursuant to what has been detected, the apparatus switches between a facsimile operation and a copying operation. There are times, however, when "on hook" signals and "off hook" signals will not be detected because of noise or temporary power outages. In such instances, the functions and operations of equipment for transmission and reception of data will not be relevant to what is happening at the telephone end.